Help converting Vs. Super Mario Bros. MAME roms to a '.nes' rom...

As the title of my thread states, I need to know how to convert/compile the coin-op arcade rom files for the Nintendo Playchoice 'VS. Super Mario Bros.' to a single '.nes' file.

For example, the (MAME) rom files:

mds-sm4.1a, mds-sm4.1b, mds-sm4.1c, etc...

compiled into a single '.nes' file that can run on an emu like nesticle or fceu ultra.

I know its possible because I do have a '.nes' version of VS SMB, but I have a modified version of game that is the MAME-type files in which i'd like to convert to the '.nes' type to play on a standard nes emulator.

The reason I am trying to do this is I found a modified MAME rom version in which one of the rom files was changed such that the 'attract mode' in the game still displayed even when the game is set to 'free play. Normally in this game on free play or if any coins are inserted the game sits on a black screen waiting for a 1P or 2P button press. This is going into an arcade cabinet that is running FCEU Ultra and I'd love to have the coin-op vs version of SMB playable on free play mode.

Can this be done and if so, how? I am not very knowledgeable when it comes to rom ripping/hacking/modding/converting.

Also, is there a specific nomenclature for these file formats (so I don't sound like a dolt next time i post a thread regarding it )